Dialysis Water Purification System

ABSTRACT

The invention comprises a control system for monitoring and operating an existing supply water pre-treatment system for supplying de-chlorinated water to dialysis purification systems. The invention includes a controller and an operator interface for programming and interacting with said control systems. The invention further includes an injection assembly having a flow turbine sensor, a reducing agent injector, and an ORP/pH sensor for monitoring and controlling ORP/pH levels of said supply water.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to and benefit of, under 35U.S.C. §120, U.S. nonprovisional patent application Ser. No. 12/945,471,filed Nov. 12, 2010 which claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/261,119, filed Nov. 13, 2009, entitled “DialysisWater Purification System”.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to a water purification systemand more specifically to a system and method for monitoring and cleaninga water pre-treatment system including backwash and regeneration of allmedia tanks used to provide water to a primary purification system.

Description of the Related Art

Dialysis systems for treatment of patients with kidney disorders are inwidespread use throughout the health care industry. These systems allrequire a constant source of purified water that removes organic andinorganic substances and microbial contaminants from the water to besupplied to a plurality of hemodialysis stations at which patients aretreated. Most dialysis water systems employ a plurality of pre-treatmentcomponents for removing these contaminants. For example, a plurality offiltration tanks such as multi-media filters, granular activated carbonfilters (GAC's), granular activated carbon polishers, and watersofteners are arranged in series to supply dechlorinated water to aprimary purification system for dialysis use.

These prior art systems require frequent, periodic cleaning to ensurethat contaminants filtered through the process do not build up in thefiltration tanks over time. Typically, these tanks must be backwashed,whereby clean water is forced in a reverse flow direction through themedia tanks and then out into a drain system to remove contaminants thatbuild up in the filtration media. The backwashing process is, in manycases, accomplished manually through operation or actuation of controlvalves that reverse fluid flow through the filtration tanks. In someprior art systems, the backwash process for each individual filtrationtank is accomplished by utilizing a timer-actuated control valve thatprovides for the flow of water in a supply or filtration directionduring a “normal” operating mode, and switches the water flow to a“backwash” mode or cycle of operation at a set time period during eachday or week depending upon the timer settings for that control valve.

However, these timer-activated systems suffer from a great number ofdisadvantages. Initially, unless an operator is actually present at thetime the backwash mode of operation is occurring, there is no way toknow that the appropriate backwash operation occurred. Additionally,since most dialysis water systems employ multiple filtration tanks suchas multi-media filters, granular activated carbon filters, and watersofteners, these tanks must be backwashed individually rather thansimultaneously since the flow of water required for a backwash or rinsecycle is quite high, and most water supply systems can't accommodatemultiple tanks backwashing simultaneously since a reduced water flowrate would not provide sufficient backwash or rinse flow. Systemcleaning typically occurs late at night when the dialysis stations arenot in use. When timer-actuated backwash operation is used, if anoperator times more than one filtration tank to backwash in the sametime period, the water flow rates to each tank may be insufficient toprovide proper contaminant reductions.

Further compounding this problem is that when backwash operations occurlate at night, an operator may not be present to determine that anincorrect backwash operation has occurred, i.e., that two or more tankshave backwashed simultaneously. In this situation dialysis water systemoperation may be suboptimal or indeed hazardous to patients since thefiltration tanks are not sufficiently cleaned to remove contaminantsfrom the water.

Additionally, in many prior art dialysis systems the contaminant levelin the water must be monitored by taking frequent samples and testingthem manually to verify that the water is sufficiently devoid ofcontaminants to be used as supply water for dialysis systems.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages of the prior art byproviding a control system for a pre-treatment system used to supplypurified water to dialysis equipment having a plurality of sensors forinteracting with the pre-treatment system and preventing improperoperation thereof, thus assuring patient safety and health.

The invention includes a controller and operator interface formonitoring the pre-treatment system, which typically includes a numberof filtration tanks for treating supply water, removing contaminantsunsuitable for use in dialysis systems. The controller is operativelyconnected to a metering pump that supplies reducing agent to watersupply 1 to remove oxidants from the supply water and scavenge oxygen,thereby reducing the chloride and chloramine levels of the supply water.

The controller is also operatively connected to a plurality of sensorsfor measuring the temperature, oxidation-reduction potential (ORP) andpH of the supply water at multiple points in the pre-treatment system.The controller can then adjust the amount of reducing agent injectedinto the water supply to accurately control the ORP/pH levels of thesupply, thereby providing consistent, clean, de-chlorinated water to afinal purification system for use in hemodialysis stations.

The invention is further capable of monitoring and adjusting thebackwash, rinse and regeneration cycles of the plurality of filtrationtanks required by the pre-treatment system and providing alarms whencycle durations or flow rates are outside of preset limits.

Other features, objects, and advantages of the invention will becomereadily apparent from the detailed description of the preferredembodiments taken in conjunction with the attached drawing Figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1A is a schematic of a dialysis water purification system inaccordance with one embodiment of the present invention.

FIG. 1B is a schematic of a dialysis water purification system inaccordance with one embodiment of the present invention.

FIG. 2 is a schematic of a dialysis water purification system inaccordance with one embodiment of the present invention.

FIG. 3 is an elevation view of sensor assembly in accordance with oneembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to FIGS. 1A-3 and in accordance with one embodiment of thepresent invention, a control system 200 is provided for operating andmonitoring a dialysis water pre-treatment system 10 that is used toproduce de-chlorinated and softened water for a primary purificationsystem 150, that in turn supplies purified water for use in a pluralityof dialysis stations 190.

Referring primarily to FIG. 2, an exemplary pre-treatment system 10 isdepicted having a supply pump 20 for pressurizing and supplying a sourceof supply water 1 to system 10 through a supply line 22 and then througha plurality of media filtration and treatment tanks. Water 1 flowsthrough supply line 22 into a series of filtration and/or softeningtanks. Initially, supply line 22 is in fluid communication with acontrol valve 30 provided on a multi-media filtration tank 40, that isused as a first stage filter to remove contaminants from supply water 1.Filtration tank 40 comprises filtration media 41 disposed in tank 40,and a riser 42 that is in fluid communication with valve 30 and a tankbottom 44. Control valve 30 comprises an inlet 32 in fluid communicationwith supply line 22, and an outlet 34, as well as a drain outlet 36 thatis in fluid communication with a system drain 37. Control valve 30 maybe actuated to provide fluid communication between inlet 32 and riser42, or outlet 34 and riser 42, as required in normal and backwash cyclesof operation.

In normal operation, wherein filtration tank 40 is in use, control valve30 connects inlet 32 to tank 40 such that supply water 1 travelsdownwardly through tank media 41, then upwardly through riser 42, whichis in fluid communication with control valve outlet 34. Incontradistinction, in a “backwash” mode of operation for cleaningfiltration tank 40, control valve 30 prohibits flow through outlet 34while connecting inlet 32 to riser 42, thereby forcing water to flowdownwardly through riser 42, into tank bottom 44, and then upwardlythrough media 41 to dislodge and remove contaminants that then exit tank40 through control valve outlet 36. It should be noted that duringbackwash operations pump 20 supplies a high volume of water 1 to providea rapid upward flow through tank 40, thereby removing impurities and“fluffing” media, which then resettles as the backwash cycle terminates.

Control valves 30 may comprise conventional electrically actuatedcontrol valves that may be programmed via an integral timer (not shown)to perform normal and backwash modes of operation at predeterminedintervals, independently of the operation of control system 200 of thepresent invention. In one embodiment of the invention, control system200 may be configured to monitor the position of control valves 30 todetermine proper cycle operation, as is disclosed below.

Pre-treatment system 10 may further comprise a first granulatedactivated carbon (GAC) filter 50, which is in fluid communication withoutlet 34 of multi-media filter 40 via a control valve 30. GAC filter 50comprises a carbon media 51, riser 52, and tank bottom 54, similar tothe construction of tank 40. During normal operation, water 1 flowsdownwardly through media 51 into tank bottom 54, then upwardly throughriser 52 and exits through valve 30 outlet 34.

Pre-treatment system may additionally include a first polisher GACfilter 60 which also uses activated carbon as a filtration medium, whichis in fluid communication with outlet 34 of GAC filter 50 via a controlvalve 30. Polisher filter 60 comprises a carbon media 61, riser 62, andtank bottom 64, similar to the construction of GAC filter 50. Duringnormal operation water 1 flows downwardly through media 61 into tankbottom 64, then upwardly through riser 52 and exits through controlvalve 30 outlet 34.

Finally, pre-treatment system 10 may include a water softener 70, whichis in fluid communication with outlet 34 of polisher tank 60 via anothercontrol valve 30. Softener 70 comprises a riser 72 and a tank bottom 74,and is typically supplied with a source of brine 76, (shown only on FIG.2) for removing hard deposits such as calcium and magnesium from supplywater 1 via the known process of ion exchange. De-chlorinated, softenedwater 2 exits softener 70 through control valve 30 outlet 34 and isrouted to primary purification system 150 through pre-treatment systemoutlet 80.

It should be noted that worker GAC 50 and polisher GAC 60 may both beoperated in a normal and backwash mode of operation, identical to thatdescribed with respect to multi-media filter 40 herein above.Furthermore, softener 70 may be operated in a normal mode as well as aregeneration mode, which is directly analogous to backwash operation offilters 40, 50 and 60.

Referring now to FIG. 1A, a similar though more elaborate pre-treatmentsystem 10 is shown, having essentially the same components as that shownin FIG. 2 except that there are two stages each of GAC filter 50 andpolisher filter 60. Supply water 1 may enter system 10 through both hotand cold water supplies, and be mixed by utilizing a blending valve 24to provide proper temperature supply water 1.

Pre-treatment system 10 outlet 80 supplies softened, de-chlorinatedwater to a primary dialysis water purification system 150 that includes,but is not limited to, a plurality of reverse osmosis filtration units160 for removing further solutes from de-chlorinated water 2, as isknown in the art. Purified water 4 flows form reverse osmosis units 160into a storage tank 170, that has an outlet 172 supplying purified water4 to a final filtration unit 180. Final filtration unit 180 providespurified water 4 through an outlet 182 sequentially to a granulizer,184, bi-carbonate mixer 186, and then to individual dialysis stations190 for use in hemodialysis, as discussed herein above.

Referring again to FIGS. 1 and 2, and in accordance with one embodimentof the present invention, control system 200 for operating andmonitoring a dialysis water pre-treatment system 10 comprises acontroller 210, having a microprocessor 212 for executing programmedinstructions, and a concomitant memory 214 for storing both data andcontroller operating system software. Controller 210 further includes aplurality of outputs 220 for supplying command signals to system 200devices, as will be discussed in greater detail below. Outputs 220 maycomprise discrete output signals of a predetermined voltage, analogsignals of varying voltage or current, or data command signals withoutdeparting from the scope of the invention.

Controller 210 additionally comprises a plurality of inputs 230 foraccepting electrical signals from system 200 devices. Inputs 230 maycomprise discrete inputs that accept signals of predetermined voltages,analog inputs that accept signals of varying voltage or current, or datasignals.

Control system 200 may additionally include an operator interface 240(sometimes termed a human-machine interface, HMI) which may, in anexemplary embodiment, comprise a touch screen display that is integralto or separate from controller 210 that permits an operator to accesscontroller 210 programming and configure various system 200 parameters.Throughout the specification operator actions relating to controller 210may be assumed to be performed through operation of operator interface240.

Control system 200 further comprises a metering pump 250, for example adigital metering pump that accepts an output 220 from controller 210representative of flow rate of fluid to be supplied by pump 250. In anexemplary embodiment pump 250 comprises a digital metering pumputilizing a stepper motor capable of varying both pump speed and strokeresponsive to an output 220 from controller 210 to supply the requestedflow rate. Metering pump has an inlet 252 that is in fluid communicationwith a supply of a liquid reducing agent 3 stored in a tank or drum 270.Additionally, metering pump 250 includes a pump outlet for supplyingmetered reducing agent 3 to pre-treatment system 10, as discussedfurther herein below. Reducing agent 3 drum 270 may include a levelswitch 272 having an output 274 operatively connected to an input 230 ofcontroller 210 for detecting and displaying on operator interface 240 alow level alarm for reducing agent 3.

Reducing agent 3 may be one of a variety of commercially availablesolutions for removing oxygen from a system. In one exemplary embodimentof the invention an aqueous solution of sodium bisulfate such asReducite™ solution is utilized as a reducing agent 3 although a widevariety of reducing agents may be employed without departing from thescope of the present invention. Reducing agent 3 scavenges oxygen andrelated oxidizing agents present in supply water 1 thereby creating apre-treatment system 10 that is hostile to microbial growth. Reducingagent 3 reacts with chlorine, forming sodium bisulfate and hydrochloricacid, and reacts with chloramines also producing ammonia. These threereaction byproducts are readily filtered by primary purification system150 reverse osmosis filters 160, thereby eliminating these contaminantsfrom water 1.

Referring now to FIG. 3 control system 200 further includes an injectionmonitoring assembly 300 comprising an injector 310, a static mixer 330,an ORP/pH sensor 340, and a flow sensor 350. Injection monitoringassembly 300 is disposed in fluid communication with supply water line22 upstream of multi-media filter 40 so that supply water 1 flowsthrough injection monitoring assembly 300. Farthest upstream in assembly300 is a flow sensor 302, shown in FIG. 3 as a turbine flow sensorthrough which supply water 1 passes, having an output signal 304 that isrepresentative of supply water 1 flow rate, operatively connected to ato an input 230 of controller 210. Flow sensor 302 allows controller 210to monitor and record supply water 1 flow rates through supply line 22both for a variety of differing purposes set forth below.

Downstream from flow sensor 302 is disposed injector 310, which includesan inlet 312 in fluid communication with outlet 254 of pump 240 and anoutlet 314 in fluid communication with water supply line 22 forinjecting reducing agent 3 into supply water 1, and thereby reducing theoxidizing potential thereof. Pump 240 supplies a metered flow ofreducing agent 3 to injector 310 for mixing with supply water 1, toreduce or change the oxidation-reduction potential and pH of supplywater 1 as required for dialysis water applications.

Injection assembly 310 comprises a static mixer 330 disposed directlydownstream from injector 310 through which water 1 and reducing agent 3flow and are mixed by the interior surfaces of static mixer 330.Directly downstream and in fluid communication with static mixer 330 andsupply line 22 is ORP/pH sensor 340 for monitoring theoxidation-reduction potential (ORP) and pH of water 1 after it is mixedwith reducing agent 3. ORP/pH sensor 340 comprises a sensor head 342that is in fluid communication with water 1 and reducing agent 3 mixtureas it passes sensor head 342. Sensor 340 further comprises an output 344that is representative of both the oxidation-reduction potential (ORP)of water 1 and the pH of water 1. Sensor 340 output 344 may comprise adigital data output 344 for proper representation of both ORP and pHthat is operatively connected to an input 230 of controller 210 so thatcontroller 210 can monitor both the ORP and pH of supply water 1 as itflows past sensor 340. This ORP/pH monitoring provides a feedbackvariable for controller 210 to use to control the flow rate of reducingagent 3 supplied by metering pump 350 through injector 310, wherebycontroller 210 may supply a greater flow of reducing agent 3 when theORP/pH level of supply water 1 is too low, or reduce the flow ofreducing agent 3 when the ORP/pH level of supply water 1 is too high.

Furthermore, sensor 340 head 342 may further comprise a temperaturesensitive element 346, for example a thermocouple or RTD that providesan additional signal on output 344 representative of supply water 1temperature, which can then be utilized in controller 210 to correct ORPand pH readings, since both the oxidation-reduction potential and pH ofwater are temperature dependent. By providing a sensor 340 that correctsfor water supply 1 temperature, controller 210 can more accuratelycalculate the flow rate of reducing agent 3 required to produce apredetermined ORP/pH level in water supply 1.

Referring again to FIGS. 1A, 1B and 2 a second ORP/pH sensor 340 mayalso be employed for use with control system 200. FIG. 1A depicts secondORP sensor 340 disposed in pre-treatment outlet line 80, to monitor theORP/pH of de-chlorinated water 2 being supplied to primary purificationsystem 150. FIG. 1B depicts a third ORP sensor disposed in outlet line182 of final filtration unit 180 to monitor the ORP/pH of purified water4 being supplied to dialysis stations 190. Where the ORP/pH detected bysecond sensor 340 in either embodiment of the invention is outside of apredetermined acceptable range, controller 210 will provide an output220 to an alarm 360 so that water 4 flow can be stopped immediately toprevent any harm to patients.

As discussed above, control valves 30 may comprise conventionalelectrically actuated control valves that may be programmed via anintegral timer (not shown) to perform normal and backwash modes ofoperation at predetermined intervals, independently of the operation ofcontrol system 200 of the present invention. Additionally, controlvalves 30 may also comprise an output 38 that provides a signalrepresentative of the position of control valves 30 to an input 230 ofcontroller 210, such that controller 210 has positive feedback fromcontrol valve 30 for a given media tank 40, 50, 60, 70 that indicateswhether the tank is in “normal” or “backwash” modes of operation. Output38 may be provided from, for example, a micro-switch located insidevalves 30 that is indicative of valve 30 position.

Furthermore, control valves 30 may also be equipped with an actuatinginput 39 that accepts an output 220 from controller 210 to initiate abackwash/regeneration cycle, moving control valve 30 into the properposition required to initiate a backwash cycle. In this embodiment ofthe invention, controller 210 may be programmed via operator interface240 to initiate backwash or regeneration cycles for filtration systems40, 50, 60 and 70 at specific times during the day or week where anoperator knows that dialysis stations 190 will not be in use. As oneexample, an operator may program multi-media tank 40 for backwash andfast rinse beginning at 2am each day, and further indicate that thebackwash portion of the cycle will take place for a set time period orduration Tbackwash, and the fast rinse will take place for a set timeperiod, Tfastrinse.

When the pre-programmed backwash time arrives for tank 40, controller210 sends an output 220 to control valve 30 of tank 40, commandingcontrol valve 30 to position itself for backwash operation wherebyentering supply water 1 flows down through riser 42 and thence upwardlythrough filter media and out to drain 36.

During this backwash mode of operation, controller 210 saves in datamemory 214 the flow rate of water 1 entering tank 40 (in, for examplegallons/min) and the time that tank 40 remains in backwash mode.Controller 210 monitors flow sensor 302 output 304 to determine the rateof supply water flow 1 to pre-treatment system 10 which is equivalent tothe backwash cycle flow rate, since tanks 40, 50, 60 and 70 ideally donot enter backwash cycles simultaneously. Controller 210 may similarlytrack the flow rate and duration of backwash flow for each tank inpre-treatment system 10. This data can be displayed on operatorinterface 240 during a backwash operation and is also saved after eachbackwash cycle is completed so that an operator can verify that thebackwash cycle of a specific tank has been completed. In this fashion,controller 210 can be pre-programmed to backwash each pre-treatmentsystem 10 tank sequentially. Since no two tanks 40, 50, 60 and 70 shouldbe backwashed simultaneously, controller 210 will prohibit theprogramming of two backwash cycles that have overlapping time periods,by prohibiting the actuation of any two control valves 30 into backwashcycles at the same time. This feature of the instant invention assuresan operator that each backwash cycle is complete before another begins.

Where controller 210 records backwash cycle data that is below apredetermined set point for either backwash cycle duration or supplywater 1 flow rate, controller 210 will provide an output 220 that may besupplied to activate a remote alarm 360, as well as provide a visualindication of an incomplete backwash cycle that is displayed as an alarmon operator interface 240. In other words, controller 210 monitors eachtank 40, 50, 60, 70 backwash cycle to assure that sufficient backwashtime and flow rate have been accomplished to assure the purity ofde-chlorinated water being supplied to primary purification system 150.

When control system 200 is integrated into existing pre-treatment 10systems, where control valves 30 each include integral timers that areprogrammed individually to enter backwash cycles at predetermined times,controller 210 may still be programmed with the predetermined backwashcycle times of each tank 40, 50, 60, 70 and monitor both the duration ofthe backwash cycle as determined by control valve 30 output 38 and theflow rate of the backwash cycle as determined by flow sensor 302. Again,controller 210 provides an alarm either via output 220 to a remote alarm360 or via operator interface 240 when a backwash cycle is ofinsufficient duration or flow rate.

Furthermore, it should be understood that each filtration tank 40, 50,60, 70 may also be required to undergo a fast rinse cycle after abackwashing cycle occurs. Controller 210 may also be programmed tomonitor both the duration and flow rates of each fast rinse cycle aswell as record the values of these variables upon cycle completion,identical to the operation disclosed with respect to the backwash cyclesdisclosed herein above. Suitable alarms may be provided if fast rinseduration and flow rates are not within predetermined acceptable limits,as set by an operator via operator interface 240.

During pre-treatment system 10 normal operation, wherein supply water 1is being pre-treated for use in primary purification system 150, controlsystem 200 performs constant monitoring and adjustment of supply water 1ORP and pH. In one embodiment of the invention, control system 200operator interface 240 provides a display that depicts ORP and pHreadings (in millivolts and pH units respectively) for each sensor 340present in system 10. Furthermore, operator interface 240 includes adisplay on operator interface 240 accessible to an operator that showsmetering pump 250 flow rate settings and the amount of reducing agent 3injected through injector 310 by pump 250. These variables may bedisplayed simultaneously as flow rates per min, per hour, and total flowvolume for a larger time period, for example a 24 hour period.

System 200 is also capable of being operated in a disinfect mode ofoperation, wherein a primary purification system disinfection cycle isinitiated. A “Loop Disinfection” display gives an operator the abilityto monitor the disinfection cycle. During the disinfection cyclecontroller 210 permits pump 20 to continue running to operate thepre-treatment system 10, even though ORP/pH sensor located at finalfiltration tank 180 will sense ORP and pH levels that are out of rangefor use during dialysis. The disinfection of primary purification system(or purified water “loop”) 150 is accomplished either manually or by aseparate control system (not shown) wherein a disinfectant such assodium hypochlorite with a pH of no greater than 7.5 is supplied toprimary purification system at a concentration of not less than 500 ppm.In this example of loop disinfection the ORP and pH levels required toaccomplish disinfection are ORP>890 and pH<7.5. Accordingly, controller210 will monitor sensor 340 disposed in primary purification systemuntil it detects ORP and pH at acceptable levels, whereupon controller210 begins a countdown timer for a predetermined time period, forexample a 30 minute dwell time. The dwell timer will continue as long asthe ORP and pH remain at acceptable levels. If they do not, the timerwill stop, and an alarm will be displayed for the operator indicatingimproper loop disinfection. Additionally, the ORP and pH setpoints, aswell as the dwell time may be programmed by an operator using interface240, to meet the demands of different systems.

The control system 200 of the present invention further provides anoperator with a plurality of alarms to indicate potential problemsrequiring alarm indications with pre-treatment system 10 that must beaddressed. Typically, alarms are displayed via an indicator of asuitable color such as red on operator interface 240, and the time thealarm occurred is recorded in a data log saved in memory 214. Criticalalarms may trigger remote alarm 360 to provide an audible alarmindication as well as a visual indication. In addition to alarms forincomplete backwash and regeneration cycles and inadequate backwash,rinse, and regeneration flow rates as discussed above, control system210 may provide the following alarms; Low supply water 1 pH level, loopdisinfection incomplete, reducing agent tank 270 level low, meteringpump 250 flow (is excessive without change) and loop ORP/pH out ofrange. The last alarm will require controller 210 to shut down pumps 20,since this condition may harm dialysis patients. Typically, controller210 will provide an alarm output 220 to controller (not shown) orprogrammable logic controller or the equivalent, that is used to operatethe primary purification system 150. This alarm output 220 is indicativeof a critical fault with pretreatment water 2, requiring that controllerto shut down primary purification system pumps to avoid potential injuryto patients.

While the present invention has been shown and described herein in whatare considered to be the preferred embodiments thereof, illustrating theresults and advantages over the prior art obtained through the presentinvention, the invention is not limited to those specific embodiments.Thus, the forms of the invention shown and described herein are to betaken as illustrative only and other embodiments may be selected withoutdeparting from the scope of the present invention, as set forth in theclaims appended hereto.

I claim:
 1. A control system for operating a pre-treatment system for awater primary purification system to provide water for dialysis, saidpre-treatment system having a supply water pump for circulatinguntreated supply water through a supply water line to said pre-treatmentsystem having at least one filtration tank for removing contaminantsfrom said supply water, wherein said at least one filtration tankcomprises a control valve for operating said tank in filtration andbackwash modes and a pre-treatment system water outlet, said controlsystem comprising: a controller having a microprocessor and concomitantdata memory, said controller further having a plurality of outputs forsupplying electrical operating signals and a plurality of inputs foraccepting electrical signals of system parameters; an OxidationReduction Potential and pH (ORP/pH) sensor in fluid communication withsaid supply line for determining the ORP and pH of said supply water; aflow sensor in fluid communication with said supply water line having anoutput of supply water flow rate operatively connected to a first inputof said controller; a first output of said controller operativelyconnected to said control valve to actuate said control valve therebyinitiating a backwash sequence of said at least one filtration tank,whereby said control valve remains actuated to control the duration ofsaid backwash sequence for a predetermined water flow rate; and a secondoutput of said controller operatively connected to said control valve toactuate said control valve for a predetermined time period and apredetermined flow rate, thereby initiating a rinse sequence of said atleast one filtration tank.
 2. A control system as claimed in claim 1further comprising: said ORP/pH sensor having output representative ofORP/pH operatively connected to an input of said controller formonitoring the ORP/pH level of said supply water as measured at saidORP/pH sensor.
 3. A control system as claimed in claim 1 comprising: asecond ORP/pH sensor having output representative of ORP/pH operativelyconnected to an input of said controller, said second ORP/pH sensordisposed downstream of said at least one filtration tank and in fluidcommunication with said pre-treatment system water outlet for monitoringthe ORP/pH level of the water as measured at said second ORP/pH sensor.4. A control system as claimed in claim 1 further comprising: acontroller input operatively connected to an output of said controlvalve of said at least one filtration tank for providing an indicationto said controller of said control valve position, whereby saidcontroller can determine whether said at least one filtration tank is ina filtration or backwash operating mode.
 5. A control system as claimedin claim 1 comprising: an input to said controller operatively connectedto said at least one filtration tank control valve to determine whethersaid at least one filtration tank is in normal or backwash mode; and anoutput of said controller representative of an alarm condition, saidoutput provided by said controller when said control valve is inbackwash mode, and when said control valve does not remain in backwashmode for a pre-determined time period and providing said alarm conditionoutput when the flow rate of said supply water as measured by said flowsensor is below a pre-determined average flow rate.
 6. A control systemfor a supply water pre-treatment system for providing de-chlorinatedwater to a primary purification system, said pre-treatment systemcomprising a supply water line in fluid communication with a pluralityof filtration tanks, each of said tanks having a control valve forplacing said tanks in normal or backwash cycles, each of said controlvalves having an actuation input for actuating said valve, and each ofsaid control valves having an output representative of control valveposition, said control system comprising: a controller having amicroprocessor and concomitant data memory and having a plurality ofoutputs for supplying electrical operating signals and a plurality ofinputs for accepting electrical signals of system parameters; an ORP/pHsensor in fluid communication with said supply water line disposeddownstream of said static mixer for determining the ORP and pH of saidsupply water, said ORP/pH sensor having an ORP and pH output signal; aflow sensor disposed in said supply water line upstream of said injectorhaving an output signal of the water flow rate through said supply waterline operatively connected to an input of said controller; a pluralityof outputs of said controller operatively connected to said actuationinputs of said control valves for placing said valves in a backwash ornormal operational cycle; a plurality of inputs of said controlleroperatively connected to a plurality of control valve position outputs;wherein said controller provides an output to a one of said controlvalves to place a one of said tanks in a backwash cycle; and whereinsaid controller monitors said backwash cycle of said one tank byverifying that said control valve is in backwash cycle for apre-determined duration, and that the flow rate of said supply water asmeasured by said flow sensor is above a predetermined average rate andproviding an alarm condition output when the flow rate of said supplywater as measured by said flow sensor is below a pre-determined averageflow rate.
 7. A control system as claimed in claim 6 wherein said OPR/pHsensor comprises: a temperature sensor having a supply water temperatureoutput, wherein said ORP/pH sensor output and said temperature sensoroutput are operatively connected to an input of said controller.
 8. Amethod for controlling a supply water pre-treatment system for providingde-chlorinated water to a primary purification system, saidpre-treatment system comprising a supply water line in fluidcommunication with a plurality of filtration tanks, each of said tankshaving a control valve for placing said tanks in normal or backwashcycles, each of said control valves having an actuation input foractuating said valve, and each of said control valves having a controlvalve position output, said method comprising: providing a controllerhaving a microprocessor and concomitant data memory and having aplurality of outputs for supplying electrical operating signals and aplurality of inputs for accepting electrical signals of systemparameters; providing an ORP/pH sensor in fluid communication with saidsupply water line disposed downstream of said static mixer fordetermining the ORP and pH of said supply water, said ORP/pH sensorhaving an output of ORP and pH; providing a flow sensor disposed in saidsupply water line upstream of said injector having an output operativelyconnected to an input of said controller representative of the waterflow rate through said supply water line; and monitoring said pluralityof filtration tanks when said control valves are in backwash cycles todetermine the time period said control valves have been in backwashposition; monitoring said supply water flow rate during said backwashcycle; providing an alarm indicative of inadequate backwash flow rate ifsaid supply water flow rate is not greater than a pre-determinedaverage; and providing an alarm of inadequate backwash duration if thetime period said control valves are in backwash position is below apredetermined minimum.
 9. A method for controlling a supply waterpre-treatment system as claimed in claim 8 comprising: monitoring saidsupply water ORP and pH levels as provided by said ORP/pH sensor; andadjusting said ORP ad pH levels of said supply water by adjusting a flowrate of said reducing agent as provided by said metering pump.
 10. Amethod for controlling a supply water pre-treatment system as claimed inclaim 10 comprising: providing an operator interface whereby andoperator may provide said controller a pre-determined average flow ratefor said backwash cycles and a duration of said backwash cycles.